Sewing-machine-motor controller



Feb; 17, 1931. D. H. CHASON SEWING MACHINE MOTOR CONTROLLER Filed Dec.16, 1927 2 Sheets-Sheet l TOR INVEN M J N ts WITNESSES Feb. 17, 1931. D.H CHASON 1,792,818

SEWING MACHINE MOTOR CONTRGLLBR Filed Dec. 16, 1927 2 Sheets-Sheet 2INVENTOR 1.3V 4 M ii ATTORNEY Patented Feb. 17,1931

UNITED s ATEsPATENr OFFICE DANIEL H. crmson, onnniznnnrmivnwJEBSEYQASSIGNOR TO THE, SINGER MA U- to the various arts, the sewingIna'chinehas rncrunme COMPANY, JERSEY .,sEwINenvrAcnnvn-Moron CONTROLLERApplication filed December 16,1927. Serial No. 2 10,5875- In thewidespread application of electricity received its share of attention,and various devices for the electric drive and-control of sewingmachines have "been-made and used. WV'hile the growing demand is for thecomplete, factory equipped,*electric sewing machine, there are in uselarge numbers of treadle-driven sewing machines which only await theadvent of a conveniently applicable and usable form ofmotor andmotorcontroller to convert them into electric machines; Thereha'slalready been provided'a sewing machine motor adapted forattac hmentto the well-known family sewing ma chine so as to become, in effect,- apermanent fixture or part of the machine, not requiring to'be removed orshifted when the machine is to be put away or made ready for use. Irefer to the electric sewing machinedescribed in the U. S. patent toDiehl and Hemleb No. 1,488,234 of March25,1924. V v

The usual sewing machine motor-controllers are of three types, 'viz.,'hand-operated, knee-operated and foot-operated. Thehandoperatedcontroller is little used as it inter feres more or less with theuse ofthe operators hands in presenting and guiding the work to the sewingmachines. The kneeoperated controller is in more general favor, andthere is practically no ob ect1on to the foot-operated controllerin-so-far-as the broad principle of foot-operation is concerned.Foot-controllers, such as heretofore coinmonly provided, have howeverbeen of the portable type comprising a pedal-operated rheostat adaptedto rest upon the floor adiacent the sewing machine table. The difficultywith-this type of foot-controller is that it has a tendency to creep orshift its position- Furthermore, it cannot be placed in a position forconvenient operation,-for the reason that the treadle-plate element ofthe sewing machine'l table occupies the floor space where thefootcontroller would be of most convenient access to the operators footand where it would be least likely to manifestits creeping tendency.

V In the ordinary drop-head sewing machine, as converted to an electricsewingmachine by the application of an electric-motor andfoot-controller, the treadle mechanism of-the sewingmachine stand hasnofunction' except as a potential foot-power drive and, as above stated,thetreadle-plate is in theway ofconvenient location of thefoot-controller;

With the idea of using the'conveniently accessible and operabletreadle-plate as a means for operating them-otor-controller, it has beenproposed to mount the-motor-controller or rheostat onthesewing machinetable and connect it by a pull-rod to the treadle-plate,

but none'of the devices heretofore proposed fills the long-felt want fora tread'le-plate opdependable construction and ofneatand inconspicuousappearance.

The present-invention has for an object or; ELIZABETH, NE-W JERSEY, Aconronnrron or NEW to provide a motor-controller to fill the want 7referred to and enable the well-known treadle-driven family sewingmachineto be readilyconverted into an electric machine. a

Further objects of the-invention will appear r in the followingdescription and claims.

According to the present improvement the motor controller is in the formof a rheostat having an operatingpull-rod with a straight or direct pulltreadle-eonnection, avoiding the use'of cams, levers,r'ock-shafts, etc.,both within and outside of the rheostat casing, and reducing theoperating mechanism to the simplest form. The rheostat is mounted withina casing one flat side face of which has secured thereto the concaveside of a special longitudinally troughed bracket which clampsbetween itand said side face, an upwardly extending arm at 'a corner of thecentral rectangular portion of the brace-member for the legs of theordinary cast-iron sewing machine stand. The bracket is formed at itslower end with divergent legs extending beyond the casing and havingfeet bent toward the plane of the side face of the rheostat casing andadaptedto rest against the upper horizontal rib and one end-rib of thecentral rectangular member of the brace.

In the accompanying drawings, Fig. 1 is a front side elevation of theusual family sewing machine as converted to an electric machine inaccordance with the invention. Fig 2 is a rear side elevation of: themotor-controller as mounted on the brace-member of the sewing machinestand; the controllercover being removed. Fig. 3 is a section on theline 3-3, Fig. 1. Fig. l is a perspective view of the bracket-memberwhich cooperates with the controller casing to hold the controllerclamped to the brace-member oi the sewing machine stand. Fig. 5 is acentral transverse vertical section through the sewing machine stand.Fig. 6 is a' section on the line 66, Fig. 1. Fig. 7 is a detail view ofthe crank-strap or upper pitman-section used for foot-power drive. Fig.8 is the rheostat pull-hook or second upper pitman-section used forelectrical operation, and Fig. 9 is the lower-pitman-section which isselectively connectible to either of the sections shown in Figs. 7 and8.

Referring more particularly to Fig. 1. 1 represents the usual drop-headsewing machine table or stand having a wooden top 2 carrying the sewinghead A. The top 2 is supported by the reticulated or ribbed cast-- ironend legs 3 connected by an intermediate ribbed cast-iron brace-member lpivot-ally carrying the usual reticulated treadle 5. The ribs of thebrace-member e are shown in 1. The brace-member is formed with a centralrectangular portion 6 from the corners of which extend arms 7 secured tothe legs 3. The brace-member 4 has mounted thereon and attached to theusual treadle-plate 5 a crank-shaft 8 carrying a belt-wheel 9 which, forfoot-power operation, is connected by the belt 10, Fig. 1, to the usualgrooved balancewheel 11 of the sewing machine.

The crank-shaft 8 is embraced by the crankstrap 12 which, for foot-poweroperation is connected to the usual trea dle-rod or pitinan 13, as shownin Fig. 5; the crank-strap constituting, in efiect, an upperpitman-section or extension 01 the pitman 13. The pitman 13 has theusual ball-and-socket connection 14 with the. treadle-plate 5 and isthreaded at 15 at its upper end to screw into the threaded socket 16,Fig. 7, oi. the crankstrap 12.

For electrical operation, the belt is removed from the balance-wheel 9and a motor 17. such for example as that shown in said Diehl and Hemlebpatent. is applied to the sewing head andconnected by a belt 18 to thebalance-wheel 11. The motor 17 is connected to the source of electricalenergy by the supply cord 19 in series with the cord 20 leading to themotor-controller 21. which, in the present instance, is a variableresistance device mounted on the brace-member 4 and including anoperating pull-rod 22 to the apertured lower end of which is connected ahook 23 having the threaded socket 24, Fig. 8 for reception of thethreaded end 15 of the pitman rod 13. As thus directly connected forelectrical operation, pressure upon the trcadleplate 5 effects adownward sliding movement of the pull-rod 22, which effects a variationof the resistance in the motor circuit and enables the speed of themotor 17 and machine A to be nicely controlled.

The motor-controller comprises a base 25 from one end of which rises anend-wall 26 having a slot through which passes the pullred 22 connectedat its inner end to the U-shaped member 27, the ends 28 of the legs ofwhich are directed toward one another but spaced apart. Recovery-springs29 serve to restore the pull-rod 22 to initial or non-running positionwith the ends 28 contacting with the stop-pins 30. The pull-rod 22 isformed with shoulders 22 which act as a stop by striking the end-wall 26and limiting the motion of the pull-rod 22 in a direction to compressthe springs 29. Mounted on the base 25 independently of the pull-rod 22and recovery-spring mechanism is the compression rheostat unit havingthe usual porcelain body 31 formed with spaced wells or chambers 32 forthe stacks of carbon resistance disks 33which substantially fill thewells 32 and are electrically connected to the terminals 34. The stacks33 also comprise the compression heads 35 which are bridged by thebow-spring contactmember 36 backed by a stiiler spring-member 37substantially in accordance with the disclosure of the patent to D. H.Chasou, No. 1,643,292 of Sept. 27, 1927. From the center of thebow-spring 36 there extends in line with the pull-rod 22 a secondpull-rod 38 having a screw-threaded end carrying an adjustable nut 39whose shank passes through the space between the ends 28 of the U-shapedmember 27. A. recovery-spring 4.0 surrounding the rod 38 is disposedbetween the body 31 and the bow-spring 36. The nut 39 is so adjustedthat the bow-spring will be carried out of contact with thepressureheads 35 by the spring 40 when the springs 29 are holding themembers 28 in engagement with the stops 30. The various parts on thebase 25 are enclosed within a suitable casing 11.

The rheostat is secured to one of the arms 7 of the brace-member 4; bymeans of a special clamp having a trough-shaped body 42 formed at itsupper end with oppositely extended arms .13 secured by screws to theflat side face of the rheostat base 25, so as to clamp the brace-member7 to such base. The body 12 of the clamp is formed at its lower end withdivergent legs 44 having feet 15 bent toward the plane of the base 25 soas to rest against the upper horizontal rib and one end rib of thecentral rectangular portion 6 of the brace 4.

By mounting the controller 21 on the brace member 4, and particularly inrear of such brace-member, it is located in a position where itsconnection withthe usual treadlepitman may be effected with greatsimplicity. Still further, it is not in a conspicuous position and,together with the cord 20, is well off of the floor and out of the way.

Having thus set forth the nature of the invention, what I claim hereinis V V 1. A sewing machine motorcontroller comprising a casing, apull-rod extending through said casing, recovery-spring means in saidcasing connected to said pull-rod, co-

' acting stops associated with said pull-rod tion adapted to claspbetween it and said casing one of the upwardly extending arms of thebrace-member of the ordinary castiron sewing machine stand, said bracketalso having diverging legs at the lower end of said body-portion, saidlegs having feet serving as rests in contact with the horizontal andvertical edges of the rectangular central portion of said brace-member.

3. The combination with the brace-member for the legs of the ordinarycast ironsewing machine stand, said brace-member having an intermediaterectangular frame-portion and arms at the corners of said rectangularframe-portion, of a rheostat having a casing formed with a side face, atreadle-operated pull-rod controlling the rheostat, and a bracket havinga longitudinally troughed body-portion embracing one of the arms of 7said brace-member, means at one end of said body-portion securing saidbracket to said rheostat casing side-face with the arm of thebrace-member clamped therebetween, said bracket having a pair ofdiverging legs at the other end of said body-portion, said legsextending beyond the rheostat casing and having feet resting against onehorizontal abnormal stresses accidentally applied to-said treadle-plate.

5 The combination with a sewing machine table having a treadle-plate, ofa motor-controller comprising 'a resistance-unit having relativelydelicate operating mechanism, a relatively strong direct-pull connectionbetween said treadle-plate and said relatively weak resistance operatingmechanism, and a stop'cooperating with an element of said relativelystrong direct-pull connection to safely take any abnormal strainsapplied to the treadle and prevent transmission of such strains to theresistance unit.

In testimony whereof, I have signed my name to this specification.

' DANIEL H. CHASON.

and one vertical edge of the rectangular frame-portion of saidbrace-member.

4. a The combination with a sewing machine table havlng a treadle-plate,of armotor-con troller comprising a compression resistance unit andoperating pull-rod, a direct-pull operating connection extending fromsaid treadle plate to said operating pull-rod and a stop cooperatingwith an element of said operating connection for preventing thetransmission to said resistance unit of any

